Ecology

Ecology is the centerpiece of our action on rivers, the Water Framework Directive is centered on acheiving “Good Ecological Status” with all measures targetting improvements in ecology.

For catchment management and river restoration to be effective, measures must benefit ecology. Without a clear line-of-sight between how a measure will have a positive ecological impact, the success of the impact and the investment into this is of limited value.

WFD Ecological Overall Status

Ecological status classifications can be composed of up to four different assessments:

  • An assessment of status indicated by a biological quality element such as fish, invertebrates or algae. We also assess for the presence of invasive species as a separate test.

  • An assessment of compliance with environmental standards for supporting physico-chemical conditions, such as dissolved oxygen, phosphorus or ammonia.

  • An assessment of compliance with environmental standards for concentrations of specific pollutants, such as zinc, cypermethrin or arsenic (these are known as ‘Annex VIII’ substances).

The lowest score in a waterbody for the above items is adopted as the “Ecological Overall” classification for that waterbody.


In The 2022 interim WFD classification for the Parrett saw 2% of waterbodies achieve Good, whilst 86% of waterbodies achieved Moderate, and 12% of waterbodies achieve Poor.

In comparison, the 2019 WFD classification saw 2% at Good, with 86% at Moderate, and 12% at Poor.

RNAGS

The Parrett has RNAGS for

Then

WFD Invertebrates Classification

Invertebrates have been used following Ecological Overall Status because they act as a proxy for water quality and physical habitat. Whilst unlike fish they are less impacted by barriers. their health provides information on the base of the food web within river ecosystems. They act as “the river canary”.

need a better justification or maybe have all included

Invertebrates (Biosys)

The below timeseries show WHPT_Total and WHPT_ASPT for all sites within Parrett catchment. WHPT Total is the sum of individual taxa scores. It reflects the overall biological quality of the water based on the presence and abundance of various taxa.

WHPT_ASP is the average score per taxon and is calculated by dividing the WHPT Total by the number of scoring taxa (NTAXA). It gives an indication of the average sensitivity of the taxa present, with higher ASPT values generally indicating better water quality.

get feedback from FBG on which metric is better to convey narrative or if both okay

The below plot shows Biosys data with WHPT Total plotted ontop of interim 2022 WFD invertebrate classifications.

Third Party Data

This initial proof of concept doesn’t include any Water Company data, only data taken directly from the Riverfly Partnership. Third-parties often have a different or un-aligned monitoring agenda to the Environment Agency. Eventually through influence, priorities can be aligned however, initially data may not be exactly where the EA would require it.

WFD Macrophytes 2022

#WFD Macrophytes 2019